The present invention relates to materials containing a polyoxometalate or a metal compound, wherein the metal compound is not a polyoxometalate. The invention further relates to methods for removing a contaminant from an environment by contacting the environment with a polyoxometalate material or a non-polyoxometalate material.
Decreasing the potential danger of contaminants from the environment has long been a significant issue. For example, the removal of offensive odors originating from cigarette smoke, sweat, exhaust gases, and rotten food in the work place, the home, and elsewhere would be quite beneficial to the public-at-large. Additionally, materials that can remove highly toxic contaminants, such as chemical warfare agents (CWAs), from the environment can ultimately reduce a soldier""s exposure to the agent. Examples of materials that would be useful include creams, powders, coatings, and fabrics.
Creams, also referred to as topical skin protectants (TSPs), have been developed to protect soldiers from the threat of dermal exposure to chemical warfare agents. TSPs require an inert material which can be applied on the skin in a thin layer to form an antipenetrant barrier to CWAs or other contact irritants that will not interfere excessively with normal skin functions. A preferred TSP affords protection against CWAs and other toxic or irritating materials in all of the forms in which they might be encountered (e.g., liquid, aerosolized liquid and vapor). Perhaps the best-known vesicant CWA is 2,2xe2x80x2-dichlorodiethylsulfide (also known as xe2x80x9cHDxe2x80x9d or xe2x80x9csulfur mustardxe2x80x9d), which was first used during World War I. Improved TSPs, however, are needed for protecting military personnel and civilians from percutaneous exposure to CWAs and protecting the skin from contact dermatitis arising from other sources as well.
U.S. Pat. No. 5,607,979 to McCreery discloses topical creams formed from about 35% to about 50% fine particulates of certain poly(tetrafluoroethylene) (PTFE) resins dispersed in perfluorinated polyether oils having viscosities from about 20 cSt to about 350 cSt. The creams afford protection against chemical warfare agents such as sulfur mustard (HD), lewisite (L), sulfur mustard/Lewisite mixtures (HL), pinacolyl methylphosphonofluoridate (soman or GD), thickened soman (TGD), and O-ethyl-S-2-diisopropylaminoethyl methylpholsphosponothiolate (VX). These creams, however, can only provide limited exposure to a CWA for a short period of time. Furthermore, the creams cannot convert the CWA to an inactive form, which will reduce the overall toxicity of the CWA.
Thus, there is a need for a material, which is also referred to herein as a support, that can remove a contaminant from the environment for an extended period of time. The incorporation of a polyoxometalate (herein referred to as xe2x80x9cPOMxe2x80x9d) into a material such as a cream, coating, powder, or fabric, is one approach to removing a contaminant from an environment. Gall et al. (Chem. Mat. 8, pp. 2523-2527, 1996) disclose the immobilization of H5PV2Mo10O40 on carbon cloth in order to determine the ability of H5PV2Mo10O40 to remove sulfur containing compounds from toluene. Johnson et al. (Proc. ERDEC Sci. Conf. Chem. Biol. Def. Res., 1998, pp. 393-399) disclose suspending H5PV2Mo10O40; K5Si(H2O)MnIIIW11O39; K4Si(H2O)MnIVW11O39; or K5CoIIIW12O40 in a perflouropolyether barrier cream to determine the creams ability to detect the presence of mustard gas. Johnson et al., however, is not concerned with the removal of the mustard gas from the gas phase.
The prior art also discloses the incorporation of polyoxometalates into powders and coatings. For example, U.S. Pat. No. 5,356,469 to Curcio et al. disclose a metal pigment composition suitable for the formation of a coating composition. The coating composition is composed of a solvent, a metal pigment, at least one phosplhosilicate pigment, and at least one heteropoly anion. The metal pigment particles possess increased stability against attack by water. Japanese patent application number 4054127 to Terumo Corp. discloses the use of heteropoly acid salts as anti-tumor agents. The heteropoly acid salts call be administered in the form of a powder or suspended in solution. Although the prior art discloses a number of different applications of polyoxometalate powders or coatings, the art does not disclose the use of a powder or coating containing a polyoxometalate to remove a contaminant from the environment.
In light of the above, it would be very desirable to have an article and a method of using an article for the removal of toxic and/or malodorous compounds without adding stoichiometric amounts of additives or compounds to the article. The present invention solves such a need in the art while providing surprising advantages. The present invention herein incorporates a polyoxometalate (POM) into a material such as a topical carrier, powder, or coating, which greatly increases the ability of the to remove a contaminant from the environment. The present invention also incorporates a metal compound, wherein the metal compound is not a polyoxometalate, into a in order to remove a contaminant from the environment.